Stop the lights: fault could halt Dublin traffic again today

Dublin commuters may face yet more traffic chaos this morning because so many sets of traffic lights at critical junctions are…

Dublin commuters may face yet more traffic chaos this morning because so many sets of traffic lights at critical junctions are effectively out of control due to a telecommunications fault.

Altogether, 140 junctions were affected by the fault, which disconnected traffic signals from Dublin Corporation's computerised traffic control system. This caused major tailbacks yesterday morning on roads leading into the city centre.

Despite efforts by the corporation's traffic engineers to mitigate the fault, peak-hour chaos was repeated yesterday evening with major arteries such as Pearse Street brought to a standstill for a period.

In a statement last night, Dublin Corporation warned that yesterday's disruption would continue this morning, but said every effort was being made to minimise inconvenience to commuters.

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In effect, traffic lights at the affected junctions were on auto-pilot, operating to a predetermined sequence that took no account of traffic volumes. The consequences were "chaotic" and "horrendous", a spokesman admitted.

He explained that the computerised traffic control system, known as SCATS, an acronym for Sydney Co-ordinated and Adaptive Traffic System, is being replaced by an upgraded version which would provide more traffic-management flexibility.

Telecom Eireann is installing the new computer links at weekends to avoid disrupting weekday traffic. However, because of a misunderstanding between Telecom and the corporation, more sites than scheduled were converted last weekend.

As a result, 140 sets of traffic signals were neither connected to the old computerised control system nor to the new one replacing it. They were operating as isolated units on a fixed-time basis, with little co-ordination.

"We are gradually putting these sites on the new system and we expect that all of the really critical junctions will be on-line by lunchtime," the corporation said. However, it declined to apportion blame for the shambles.

Mr Conor Faughnan, spokesman for the Automobile Association, said he had been told 65 of the 140 junctions had been reconnected to the SCATS system by mid-afternoon yesterday and that more would follow by this afternoon. But he added that the severe peak-hour tailbacks in areas such as Dame Street and Pearse Street "demonstrate the city's vulnerability if something like a computer problem can have that sort of impact on traffic."

A spokeswoman for Telecom Eireann confirmed it was carrying out the work on behalf of Dublin Corporation, but she said it had nothing to add to the explanation given by the corporation for yesterday's chaos.

Junctions are to be redesigned to reduce accidents: page 7

Frank McDonald

Frank McDonald

Frank McDonald, a contributor to The Irish Times, is the newspaper's former environment editor